A birdfeeder which operates with a perch that is controlled by the use of magnetic force that allows certain smaller birds to freely feed while inhibiting larger birds and small animals, such as squirrels, from feeding is provided. The birdfeeder has a plurality of movable pivoted perches which move from a first position to a second position. In the first (horizontal) position, a small bird may sit on the movable perch and reach an opening in a food hopper while the weight of a larger bird or animal will force the movable perch downward into the second position wherein the perch is moved away from the opening in the food hopper. A magnet located on an end of the movable perch secures the perch in the first position until the weight of a larger bird or animal causes the movable perch to pivot to the non-horizontal position.
Attempts have been made to provide improved birdfeeder wherein smaller birds may feed while larger birds and other heavier animals are prevented from feeding. For example, U.S. Pat. No. 6,192,832 to Husnik discloses a fully rotatable squirrel proof bird feeder for dislodging and preventing unwanted animals comprising a horizontal shaft with rotatable end sleeves, a seed receptacle with feed portals disposed midpoint and fixed to the shaft, and a counter-weighted shell comprising a window opening, weather awning, and rotatable perch assembly. The shell is mounted fully rotatable on the shaft closely surrounding the seed receptacle. Vertical braces fixed to the shaft ends prevent axial rotation of the seed receptacle and provide a secure method for hanging. An adjustable counter-weight fixed to the shell permits weight discrimination and biases alignment between the window opening and the feed portals. In the open feeding position, birds of preferential weight land on the perch and pass through the window opening to the feed portals. In the closed rotating position(s), heavier unwanted animals upon the feeder will roll the shell, the shaft sleeves, or the perch clockwise or counterclockwise and either be dislodged or the shell will close off access to the feed portals. An alternate embodiment integrates various features and counterbalance properties by molding the shell body shape and changing the pivot location of the shell.
Further, U.S. Pat. No. 6,050,221 to Eaton discloses a bird feeder that prevents animals such as squirrels, chipmunks, and rodents from gaining access to feed in the bird feeder. The bird feeder protects the feed from wind, rain, and snow. The bird feeder includes a housing that is rotatably attached to a support shaft allowing at least 360 degrees of rotation. The housing includes a plurality of angled plates that cause the housing to spin when the animal contacts one of the plates. A feed tray is rigidly attached to the support shaft and remains upright and stationary within the housing while the housing rotates about the support shaft. A bird can fly through an opening directly to the feed tray. The transparent sides of the housing allow a person to watch the bird.
However, these birdfeeders fail to provide a birdfeeder which utilizes a magnetic perch which rotates around a pivot from a first position to a second position and which allows a user to selectively determine the weight of the bird which may feed from the birdfeeder.